The present invention relates to devices for punching holes in stacks of paper sheets are the like for accomodating various loose leaf binder systems. Specifically the present invention relates to an apparatus for simultaneously selecting a specific array of electrically powered punching dies required by a specific loose leaf binder design.
Devices for punching holes in paper or the like have been known extensively in the past. Single punch devices have been found to be slow and difficult to manually align.
U.S. Pat. No. 3,987,695, issued to Neilson, discloses a single punch device with a rotatable multifaced bar, each face having a series of indents marking the location of a hole for a particular array of holes. A face of the bar is selected, the punch is pulled along the length of the face until an indent is encountered, at which time the punch is hand operated to form a hole. This concept, although providing alignment is extremely labor intensive and slow to operate, and is limited in a number of arrays that it can accomodate.
U.S. Pat. No. 2,985,052, issued to Mentzer et al, discloses a device for simultaneously punching a plurality of aligned holes. A plurality of uniformly spaced punches may be selectively engaged with an electric motor or the like. This provides some selectivity, but the engagement of the holes must be done individually, consequently conversion from one array to another is extremely slow and subject to human error. Also, the explicit limitation to uniform spacing of the punching dies may exclude many common arrays of loose leaf binder holes.
Thus, it is desirable to provide an apparatus for quickly and accurately modifying a punching apparatus when converting to and from various arrays of hole patterns.